Philipp Chapkovski

Do wars change preferences for redistributive state policies? We analyze this question using a preregistered survey experiment involving N=3920 respondents in Russia conducted during the Russo-Ukrainian war. The order of questions in the survey was manipulated to remind some respondents of the war before measuring the outcome variables. We find that among individuals who favor the war, the war reminder increases preferences for redistribution. Our two-part design allows us to investigate the channels for this effect; we find that it is partly due to increased trust in the government. We also observe an increase in prosocial preferences among individuals who support the war, but this effect is not associated with the increase in redistribution preferences.

Some theories in economics and psychology propose that background uncertainty, which is uncertainty that is independent of a person’s actual decision, can alter people’s risk-taking behavior with respect to that decision. However, previous empirical research mostly relying on single experiments is inconclusive regarding the existence of this effect. Here, we systematically investigate the effect of background uncertainty on decision-making. After reviewing the literature, we argue that two types of background uncertainty should be distinguished: (a) background ambiguity, where the decision maker does not know the probability of the outcomes of the background event, and (b) background risk, where the outcome probabilities are known. We tested the hypotheses (i) that background uncertainty does affect risk-taking in the decision at hand, and (ii) the type of background uncertainty moderates that effect. In four experiments (total N =863), we induced background uncertainty (ambiguity or risk) using different methods and measured risk-taking with multiple behavioral tasks. We did not find a significant effect of background uncertainty on risk-taking behavior.

We study the effect of gamification on retail traders’ behavior using a randomized online experiment. Participants with lower financial literacy prefer platforms with hedonic gamification elements, such as confetti and achievement badges. On average, hedonic gamification increases trading volume by 5.17%. However, the difference in trading activity between gamified and nongamified platforms is driven primarily by self-selection (70%) rather than gamification (30%). Participants who prefer hedonic gamification exhibit noisy trading strategies, whereas those favoring nongamified platforms display stronger contrarian behavior. Further, price trend notifications enhance learning for investors with accurate beliefs, but they reinforce trading mistakes for those with incorrect beliefs.This paper has been This paper was accepted by Jean-Edouard Colliard for the special issue on the human-algorithm connection.Funding: P. Chapkovski acknowledges funding from the Deutsche Forschungsgemeinschaft [Germany’s Excellence Strategy—EXC 2126/1-390838866]. M. Khapko and M. Zoican acknowledge the Social Sciences and Humanities Research Council of Canada [Insight Development Grant 430-2018-00125] and the Canadian Securities Institute Research Foundation [research grant]. M. Zoican acknowledges financial support from the Quantitative Management Research Initiative (QMI) under the aegis of the Fondation du Risque, a joint initiative by Université Paris-Dauphine, l’École Nationale de la Statistique et de l’Administration ParisTech, and LFIS, France.Supplemental Material: The online appendix and data files are available at https://doi.org/10.1287/mnsc.2022.02650.